Their king, Penguin King likes bowling & his minions can turn into bowling pins. In the episode, Penguin Castle, Penguin King told Commander ApeTrully he would join Big Green if he won one his bowling challenges. But he failed so the penguins took him hostage. First squad even had trouble making peace with them as they all failed his bowling challenges and Mighty Ray even damaged his castle. Angry, he made clones of them and had them fight themselves until they remembered what Mr. No Hands said. After a long battle the penguins and their penguin clones, Penguin King loses & joins Big Green with his Penguins after realising that Humans aren't as cowardly as High Roller told him.

Penguins

The penguins skin is actually armour that makes them immune to all attacks. The only way to defeat them is to juggle them and make them dizzy.